--- a/libdjvu/DjVuPort.cpp +++ a/libdjvu/DjVuPort.cpp @@ -507,10 +507,19 @@ GP DjVuPortcaster::id_to_file(const DjVuPort * source, const GUTF8String &id) { GPList list; + + if (!!opening_id && opening_id == id) + G_THROW( ERR_MSG("DjVuPortcaster.recursive_open") ); + else + opening_id = id; + compute_closure(source, list, true); GP file; for(GPosition pos=list;pos;++pos) if ((file=list[pos]->id_to_file(source, id))) break; + + opening_id = GUTF8String(); + return file; } --- a/libdjvu/DjVuPort.h +++ a/libdjvu/DjVuPort.h @@ -484,6 +484,7 @@ private: const DjVuPort *dst, int distance); void compute_closure(const DjVuPort *src, GPList &list, bool sorted=false); + GUTF8String opening_id; };